#ifndef MM_SLAB_H
#define MM_SLAB_H
/*
 * Internal slab definitions
 */

/*
 * State of the slab allocator.
 *
 * This is used to describe the states of the allocator during bootup.
 * Allocators use this to gradually bootstrap themselves. Most allocators
 * have the problem that the structures used for managing slab caches are
 * allocated from slab caches themselves.
 */
enum slab_state {
        DOWN,                   /* No slab functionality yet */
        PARTIAL,                /* SLUB: kmem_cache_node available */
        PARTIAL_ARRAYCACHE,     /* SLAB: kmalloc size for arraycache available */
        PARTIAL_NODE,           /* SLAB: kmalloc size for node struct available */
        UP,                     /* Slab caches usable but not all extras yet */
        FULL                    /* Everything is working */
};

extern enum slab_state slab_state;

/* The slab cache mutex protects the management structures during changes */
extern struct mutex slab_mutex;

/* The list of all slab caches on the system */
extern struct list_head slab_caches;

/* The slab cache that manages slab cache information */
extern struct kmem_cache *kmem_cache;

unsigned long calculate_alignment(unsigned long flags,
                unsigned long align, unsigned long size);

#ifndef CONFIG_SLOB
/* Kmalloc array related functions */
void create_kmalloc_caches(unsigned long);

/* Find the kmalloc slab corresponding for a certain size */
struct kmem_cache *kmalloc_slab(size_t, gfp_t);
#endif


/* Functions provided by the slab allocators */
extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags);

extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
                        unsigned long flags);
extern void create_boot_cache(struct kmem_cache *, const char *name,
                        size_t size, unsigned long flags);

struct mem_cgroup;
#ifdef CONFIG_SLUB
struct kmem_cache *
__kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size,
                   size_t align, unsigned long flags, void (*ctor)(void *));
#else
static inline struct kmem_cache *
__kmem_cache_alias(struct mem_cgroup *memcg, const char *name, size_t size,
                   size_t align, unsigned long flags, void (*ctor)(void *))
{ return NULL; }
#endif


/* Legal flag mask for kmem_cache_create(), for various configurations */
#define SLAB_CORE_FLAGS (SLAB_HWCACHE_ALIGN | SLAB_CACHE_DMA | SLAB_PANIC | \
                         SLAB_DESTROY_BY_RCU | SLAB_DEBUG_OBJECTS )

#if defined(CONFIG_DEBUG_SLAB)
#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
#elif defined(CONFIG_SLUB_DEBUG)
#define SLAB_DEBUG_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
                          SLAB_TRACE | SLAB_DEBUG_FREE)
#else
#define SLAB_DEBUG_FLAGS (0)
#endif

#if defined(CONFIG_SLAB)
#define SLAB_CACHE_FLAGS (SLAB_MEM_SPREAD | SLAB_NOLEAKTRACE | \
                          SLAB_RECLAIM_ACCOUNT | SLAB_TEMPORARY | SLAB_NOTRACK)
#elif defined(CONFIG_SLUB)
#define SLAB_CACHE_FLAGS (SLAB_NOLEAKTRACE | SLAB_RECLAIM_ACCOUNT | \
                          SLAB_TEMPORARY | SLAB_NOTRACK)
#else
#define SLAB_CACHE_FLAGS (0)
#endif

#define CACHE_CREATE_MASK (SLAB_CORE_FLAGS | SLAB_DEBUG_FLAGS | SLAB_CACHE_FLAGS)

int __kmem_cache_shutdown(struct kmem_cache *);

struct seq_file;
struct file;

struct slabinfo {
        unsigned long active_objs;
        unsigned long num_objs;
        unsigned long active_slabs;
        unsigned long num_slabs;
        unsigned long shared_avail;
        unsigned int limit;
        unsigned int batchcount;
        unsigned int shared;
        unsigned int objects_per_slab;
        unsigned int cache_order;
};

void get_slabinfo(struct kmem_cache *s, struct slabinfo *sinfo);
void slabinfo_show_stats(struct seq_file *m, struct kmem_cache *s);
ssize_t slabinfo_write(struct file *file, const char __user *buffer,
                       size_t count, loff_t *ppos);

#ifdef CONFIG_MEMCG_KMEM
static inline bool is_root_cache(struct kmem_cache *s)
{
        return !s->memcg_params || s->memcg_params->is_root_cache;
}

static inline bool cache_match_memcg(struct kmem_cache *cachep,
                                     struct mem_cgroup *memcg)
{
        return (is_root_cache(cachep) && !memcg) ||
                                (cachep->memcg_params->memcg == memcg);
}

static inline void memcg_bind_pages(struct kmem_cache *s, int order)
{
        if (!is_root_cache(s))
                atomic_add(1 << order, &s->memcg_params->nr_pages);
}

static inline void memcg_release_pages(struct kmem_cache *s, int order)
{
        if (is_root_cache(s))
                return;

        if (atomic_sub_and_test((1 << order), &s->memcg_params->nr_pages))
                mem_cgroup_destroy_cache(s);
}

static inline bool slab_equal_or_root(struct kmem_cache *s,
                                        struct kmem_cache *p)
{
        return (p == s) ||
                (s->memcg_params && (p == s->memcg_params->root_cache));
}

/*
 * We use suffixes to the name in memcg because we can't have caches
 * created in the system with the same name. But when we print them
 * locally, better refer to them with the base name
 */
static inline const char *cache_name(struct kmem_cache *s)
{
        if (!is_root_cache(s))
                return s->memcg_params->root_cache->name;
        return s->name;
}

static inline struct kmem_cache *cache_from_memcg(struct kmem_cache *s, int idx)
{
        if (!s->memcg_params)
                return NULL;
        return s->memcg_params->memcg_caches[idx];
}

static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
{
        if (is_root_cache(s))
                return s;
        return s->memcg_params->root_cache;
}
#else
static inline bool is_root_cache(struct kmem_cache *s)
{
        return true;
}

static inline bool cache_match_memcg(struct kmem_cache *cachep,
                                     struct mem_cgroup *memcg)
{
        return true;
}

static inline void memcg_bind_pages(struct kmem_cache *s, int order)
{
}

static inline void memcg_release_pages(struct kmem_cache *s, int order)
{
}

static inline bool slab_equal_or_root(struct kmem_cache *s,
                                      struct kmem_cache *p)
{
        return true;
}

static inline const char *cache_name(struct kmem_cache *s)
{
        return s->name;
}

static inline struct kmem_cache *cache_from_memcg(struct kmem_cache *s, int idx)
{
        return NULL;
}

static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
{
        return s;
}
#endif

static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
{
        struct kmem_cache *cachep;
        struct page *page;

        /*
         * When kmemcg is not being used, both assignments should return the
         * same value. but we don't want to pay the assignment price in that
         * case. If it is not compiled in, the compiler should be smart enough
         * to not do even the assignment. In that case, slab_equal_or_root
         * will also be a constant.
         */
        if (!memcg_kmem_enabled() && !unlikely(s->flags & SLAB_DEBUG_FREE))
                return s;

        page = virt_to_head_page(x);
        cachep = page->slab_cache;
        if (slab_equal_or_root(cachep, s))
                return cachep;

        pr_err("%s: Wrong slab cache. %s but object is from %s\n",
                __FUNCTION__, cachep->name, s->name);
        WARN_ON_ONCE(1);
        return s;
}
#endif


/*
 * The slab lists for all objects.
 */
struct kmem_cache_node {
        spinlock_t list_lock;

#ifdef CONFIG_SLAB
        struct list_head slabs_partial; /* partial list first, better asm code */
        struct list_head slabs_full;
        struct list_head slabs_free;
        unsigned long free_objects;
        unsigned int free_limit;
        unsigned int colour_next;       /* Per-node cache coloring */
        struct array_cache *shared;     /* shared per node */
        struct array_cache **alien;     /* on other nodes */
        unsigned long next_reap;        /* updated without locking */
        int free_touched;               /* updated without locking */
#endif

#ifdef CONFIG_SLUB
        unsigned long nr_partial;
        struct list_head partial;
#ifdef CONFIG_SLUB_DEBUG
        atomic_long_t nr_slabs;
        atomic_long_t total_objects;
        struct list_head full;
#endif
#endif

};

void *slab_next(struct seq_file *m, void *p, loff_t *pos);
void slab_stop(struct seq_file *m, void *p);